Alex and Ruby are the proud owners of R.A.D. Agency (Radically Awesome Detectives!) Along with their feline sidekick, Sherlock, (who also happens to be tailless) the two middle schoolers solve local mysteries and accept payment in cookies. (Chocolate chip, thank you very much.) When the sixth grade Santa robot goes missing (...pssst. His name is Mr. Jingles!), Alex and Ruby must solve the case of its disappearance and catch the thief. But with only five days left before vacation break-and multiple suspects-this case proves harder than they first thought. The stakes are raised when their teacher, Miss Chang, threatens to cancel their holiday party! Will they solve the mystery in time to save their party and their reputation?